1. Field of the Invention
This invention relates to a torsional vibration damper, in particular for clutches on motor vehicles, with a driving-side transmission element with at least one sun gear which can rotate relative to the transmission element and is provided with at least one planet wheel which is engaged on one hand with a sun gear and on the other hand with a ring gear, and with a driven-side transmission element, whereby one of the transmission elements has actuating means for a spring device.
2. Background Information
German Patent No. 31 39 658 C2, FIGS. 3 and 4 in particular, appears to disclose a torsional vibration damper with a driving-side transmission element in the form of a lining carrier, which lining carrier is rigidly connected to a sun gear of a planetary gearset located on a hub, the hub acting as a driven-side transmission element. The planetary gearset has a planet carrier which is capable of executing a limited rotation relative to the lining carrier. The planet carrier is fastened to the hub, and the planet wheels are mounted on the planet carrier. The planet wheels are engaged, on one hand, with the sun gear and, on the other hand, with a ring gear fastened to the cover plate for the hub, which cover plate can rotate relative to the hub. The cover plates each have respective recesses for a spring device, which recesses are bordered by stop edges, or fitting edges, or stop surfaces, for the respective spring device.
In the torsional vibration damper described immediately above, a torque, generated by a drive mechanism, is introduced to the sun gear via the lining carrier. When the planet wheels are rolling, torque fluctuations cause a relative rotation of the planet carrier and ring gear with respect to one another, which relative rotation causes a change in the position of the cover plates with respect to the hub, thereby deforming the spring devices.
By means of an appropriate selection of the translation ratio, transformation ratio, gear ratio, or transmission ratio, on the planetary gearset, the angle of rotation for the deformation of the spring elements can be changed, in contrast to a torsional vibration damper without a planetary gearset, and thus the disruptive influence of torque fluctuations can be reduced. On account of the low mass moment of inertia on the driven-side in such torsional vibration dampers, however, the ability to absorb rather large fluctuations of the torque is limited.
To be able to absorb rather large torque fluctuations, a flywheel with two centrifugal masses of the type disclosed in German Patent No. 36 30 398 C2, for example, has apparently turned out to be advantageous. On that flywheel, a spring device is located between a driving-side centrifugal mass and a driven-side centrifugal mass, and this spring device makes possible a relative movement of the two centrifugal masses with respect to one another. On such two-mass flywheels, introduced torques are transmitted to the driven side, but without translation, transmission, or conversion, in the torsional vibration damper.